Unbiased estimators of ability parameters, of their variance, and of their parallel-forms reliability Article Received: 04 June 1982 Revised: 12 October 1982 DOI:
Cite this article as: Lord, F.M. Psychometrika (1983) 48: 233. doi:10.1007/BF02294018 Abstract
Given known item parameters, unbiased estimators are derived i) for an examinee's ability parameter
θ and for his proportion-correct true score ς, ii) for the variances of θ and ς across examinees in the group tested, and iii) for the parallel-forms reliability of the maximum likelihood estimator \(\hat \theta\). Key words item response theory true score latent trait theory maximum likelihood
This work was supported in part by contract N00014-80-C-0402, project designation NR 150-453 between the Office of Naval Research and Educational Testing Service. Reproduction in whole or in part is permitted for any purpose of the United States Government.
Sympson, J. B.
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© The Psychometric society 1983